When Mel Lintern says gold grows on trees, he isn’t kidding. Lintern is a geochemist with the Commonwealth Scientific and Industrial Research Organisation, or CSIRO, in Kensington, Western Australia. A team he headed has just announced finding tiny grains of the precious metal in the leaves of eucalyptus trees.

If you’re picturing gold leaves glittering in the sun, forget it. The specks of leaf-bound gold are only one-fifth the width of a human hair and just about as long, Lintern points out. ...